Low
doses of nonylphenol have profoundly adverse effects on oysters.
A single exposure during larval development to an environmentally-relevant
dose of nonylphenol causes disruption of sexual development, and
also lowers survival of offspring in the next generation. Exposed
larvae are much more likely to develop as hermaphrodites, and the
sex ratio is altered, with more females than expected. According
to the scientists who conducted the research, exposure "may
result in severe consequences, not only for natural populations
but also for commercial hatcheries situated in areas where nonylphenol
is present in the water. More...

A combined
lab and field study of the leopard frog, Rana pipiens, implicates
atrazine in widespread feminization of males during tadpole development
and metamorphosis. The lab studies confirmed earlier findings
from a different amphibian, the African clawed toad, that extremely
low levels of atrazine causes significant gonadal abnormalities in
male frogs. The
field studies demonstrate widespread abnormalities in wild populations
of the frog and link them to the geography of atrazine use. More...

23
July 2002. An elegant series of field and laboratory experiments
with wood frogs reveals that pesticides
(atrazine, malathion and esfenvalerate) at very low levels damage
the frogs' immune system and thereby impair their ability to resist
infection by parasites. The parasite cysts imbedded in
the growing tadpole then cause limb deformities. It thus appears
that what had thought to be two competing
ideas about why deformities have become so common—parasites
vs. pesticides— are actually working in concert together.
More...

15
April 2002 Research by scientists at the University of California,
Berkeley, reveals that the most abundantly used herbicide
in the world, atrazine, disrupts the development of frogs at extraordinarily
low levels of exposure. Over 15% of males of the classic
"laboratory rat" of the frog world, Xenopus laevus,
developed hermaphroditic reproductive tracts when exposed, during
development, to 0.1 parts per billion atrazine. The
researcher team, led by Dr. Tyrone Hayes,also noted demasculinization
of secondary sexual characteristics and alterations in serum hormone
levels. More...

23
June 2001. A team of scientists from Northern Arizona University
reports that endosulfan at very low levels disrupts reproductive
communication between male and female salamanders by altering
the development of glands involved in pheremone production.
Exposed females of the red-spotted newt Notophthalmus viridescens,
a North American salamander, then suffer lowered mating success.
Contaminant levels sufficient to cause an effect -- 5 parts per
billion-- are far beneath water quality standards mandated by the
US EPA for this commonly used pesticide. More...

16
February 2001. New research on tadpoles of the North American gray
treefrog reveals an unexpected interaction between a common
pesticide, carbaryl, and stress induced in the tadpoles by
predators. Without the predator-induced stress, short-term
exposure to low levels of carbaryl had no effect on survival. Longer
exposure increased mortality. By far the highest mortality, however,
was caused by exposure to carbaryl while in the presence of a predator.
Up to 97% of tadpoles died under these conditions. [The experiments
were conducted in a way that the tadpoles could sense the predator's
presence but the predator could not reach them.] These results
indicate that frogs are far more sensitive to pesticides in real-world
conditions than traditional toxicity testing will ever reveal. More...

15
December 2000. Writing in Environmental Health Perspectives,
the journal of the National Institute of Environmental Health Sciences,
scientists report widespread feminization of an endangered
fish, the chinook salmon, breeding in central Washington on the
Hanford Reach of the Columbia River. Of females sampled on spawning
grounds, 84% are chromosomal males. Two plausible causes: higher
water temperatures or endocrine disruption. More...

18
September 2000.In
a news
story covered by ENN, The Qikiqtaaluk Wildlife Board and the World
Wildlife Fund report that a new survey reveals the impact of pollution
on arctic wildlife. Hunters and elders from four Canadian arctic
villages participated in the survey. Among them they have a combined
hunting experience of about 800 years. "Hunters and elders from
every community talked about abnormalities in at least one of the
species they harvest regularly - caribou, seal, walrus, beluga, narwhal
and polar bear. " "Almost half of the survey's participants
said they see increasing abnormalities."

6
September 2000. The BBC reports that endocrine disruption of fish
is widespread in northern Europe, with confirmations obtained
from 5 of 7 countries examined. Up to 100% of fish are affected in
some river systems. A combination of industrial compounds and human
urinary metabolites (from drugs) appear to be the cause. More...

The
BBC reports that one percent of polar bears on the Arctic island or
Svarlbard are hermaphroditic, and scientists studying this unnatural
phenomenon believe it is due to endocrine disrupting chemicals. More...

4
July 2000. Researchers report that whale and dolphin meat sold in
Japan for human consumption is contaminated heavily by dioxin. More...

Exposure
in the egg to DDT can cause complete sex reversal in a species
of fish. The male-to-female reversal in Japanese medaka Oryzias
latipes can be complete, permanent, and functional after a onetime
embryonic exposure to the contaminant. Exposed fish that carry
chromosomes typical for males of this species have fully functional
oviducts and bear fertile offspring. More...

Arochlor 1242, chlordane and trans-nonachlor alter sexual differentiation
during embryonic development in turtles, leading to changes in the
ratio of males:females hatched. These compounds also alter circulating
hormone levels of hatchling turtles exposed as embryos in the egg.
More...

Atlantic
Salmon are now virtually extinct in most of their original range
in New England and eastern Canada. A
major contributor to their decline now appears to be the disruption
of hormonal control of their ability to adjust to salt water during
migration to the sea. Surprisingly, the impact is from a compound,
nonylphenol, used as an "inert" surfactant in a pesticide,
not the component of the pesticide thought to be biologically active.
More...

Dioxin in the sediments and waters of the Great Lakes induces very
high mortality in Lake Trout fry (immediately post-hatching).
This now appears to be an important contributor to the cataclysmic
decline of that commercially important fishery.More...

Frog deformities--extra legs, misplaced eyes, missing limbs, mishapen
extremeties--are being detected at levels drastically above any rate
which might plausibly be thought to be natural. Several factors,
including contamination, appears to be contributing to this phenomenon.
The importance of different factors appears to vary from one place
to another. More...

Two
established reproductive toxins in people, dibromochloropropane (DBCP)
and ethylene dibromide (EDB), may have contributed to population
declines in American Alligators. More...

Fish feminization is widespread in Great Britain and in the US.
The causes now appear to be a mixture of chemicals, including
excreted byproducts of birth control pills and industrial chemicals.More...

Types
of animals throughout the animal kingdom use hormones or hormone-like
signals to guide development from embryo to adulthood. Most
of the attention has been focused on vertebrate species--mammals,
birds, fish, amphibians, reptiles. But most of the animal kingdom
is invertebrate. New studies reveal invertebrate species' vulnerability
to endocrine disruption. More...